I sort of ran out of steam at some point, but this is a good chunk of them. Most of these are relatively automatic replacements, only 5fc6777b could perhaps use a second pair of eyes, to see whether I've made any illegal transformations.
Commit summary
5fc6777b Reduce head usage
8f735acd Import X.Prelude unqualified if necessary
This gets rid of, for example,
The import of ‘liftA2’ from module ‘XMonad.Prelude’ is redundant
-type warnings.
9399a1e8 X.{U,H}.Debug{Window,Events}: Replace tail with non-empty lists
ec3a9eea X.L.Groups: Rewrite gen using infinite streams
3a3544b5 X.Prelude: Add infinite stream type
Stolen from X.A.MostRecentlyUsed. This can be used in favour of lists
when we know the generated lists are definitely infinite.
fab8ad5b X.U.Stack: Add differentiateTwo
cbb85248 Replace tail with drop 1
Where appropriate.
c8c81474 X.A.CycleWindows: Move rot{Up,Down} to X.A.RotSlaves
[ ] I've considered how to best test these changes (property, unit,
manually, ...) and concluded:
I haven't installed GHC 9.8 (yet), so this is mostly untested. Everything should work, though.
[x] I updated the CHANGES.md file
Where appropriate.
Remaining nits
Remaining nits…
XMonad/Layout/OneBig.hs:68:22: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
68 | master = head ws
| ^^^^
XMonad/Layout/MultiColumns.hs:100:47: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
100 | where newval = max 0 $ head r + x
| ^^^^
XMonad/Util/Image.hs:45:26: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
45 | imageDims img = (length (head img), length img)
| ^^^^
XMonad/Actions/Workscreen.hs:112:40: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
112 | let ws = head . workspaces $ a !! wscrId
| ^^^^
XMonad/Actions/SwapPromote.hs:243:30: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
243 | mh = let w = head . W.integrate $ s3
| ^^^^
XMonad/Hooks/ServerMode.hs:95:35: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
95 | let atom = fromIntegral (head dt)
| ^^^^
XMonad/Actions/WorkspaceCursors.hs:100:34: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
100 | where x = end $ map return $ head a
| ^^^^
XMonad/Util/Timer.hs:56:43: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
56 | if mt == a && dt /= [] && fromIntegral (head dt) == ti
| ^^^^
XMonad/Hooks/Place.hs:196:49: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
196 | let (workspace, screen) = head infos
| ^^^^
XMonad/Prompt.hs:537:21: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
537 | let defaultMode = head modes
| ^^^^
XMonad/Prompt.hs:647:26: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
647 | return $ head l
| ^^^^
XMonad/Prompt.hs:779:76: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
779 | if command st == hlCompl then put st else replaceCompletion (head cs)
| ^^^^
XMonad/Prompt.hs:1386:13: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
1386 | let c = head s
| ^^^^
XMonad/Prompt.hs:1594:43: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
1594 | (asc, desc) <- io $ textExtentsXMF fs $ head compl
| ^^^^
XMonad/Prompt.hs:1795:25: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
1795 | deleteConsecutive = map head . group
| ^^^^
XMonad/Actions/WindowGo.hs:93:70: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
93 | ifWindow qry mh = ifWindows qry (windows . appEndo <=< runQuery mh . head)
| ^^^^
XMonad/Actions/WindowGo.hs:168:30: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
168 | _ -> windows . focusFn . head $ ws
| ^^^^
XMonad/Prompt/OrgMode.hs:528:26: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
528 | str <- munch (/= head ptn)
| ^^^^
XMonad/Hooks/StatusBar/PP.hs:467:14: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
467 | in fst $ head $ dropWhile (uncurry (/=)) $ zip xs $ tail xs
| ^^^^
XMonad/Hooks/Minimize.hs:47:36: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
47 | let message = fromIntegral . head $ dt
| ^^^^
XMonad/Util/ExclusiveScratchpads.hs:177:11: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
177 | mh <- head . map hook <$> ys -- ys /= [], so `head` is fine
| ^^^^
XMonad/Util/ExclusiveScratchpads.hs:178:11: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
178 | n <- head . map name <$> ys -- same
| ^^^^
XMonad/Layout/Combo.hs:124:63: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
124 | (maybe super head msuper')
| ^^^^
XMonad/Layout/Combo.hs:125:60: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
125 | (maybe l1 head ml1')
| ^^^^
XMonad/Layout/Combo.hs:126:60: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
126 | (maybe l2 head ml2')
| ^^^^
XMonad/Layout/TallMastersCombo.hs:247:61: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
247 | let subMaster = if null w2 then Nothing else Just $ head w2
| ^^^^
XMonad/Layout/TallMastersCombo.hs:254:61: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
254 | let subMaster = if null w2 then Nothing else Just $ head w2
| ^^^^
XMonad/Actions/GridSelect.hs:661:61: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
661 | s = TwoDState { td_curpos = head coords,
| ^^^^
XMonad/Util/EZConfig.hs:441:23: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
441 | combine ks = (head . fst . head $ ks,
| ^^^^
XMonad/Util/EZConfig.hs:441:36: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
441 | combine ks = (head . fst . head $ ks,
| ^^^^
XMonad/Util/EZConfig.hs:443:29: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
443 | fstKey = (==) `on` (head . fst)
| ^^^^
XMonad/Util/EZConfig.hs:547:27: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
547 | dups = map (snd . head)
| ^^^^
XMonad/Actions/Navigation2D.hs:887:38: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
887 | newwinset = winset { W.current = head newscrs
| ^^^^
XMonad/Actions/Prefix.hs:169:37: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from XMonad.Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
169 | Raw a -> replicate a (head events) ++ [key]
| ^^^^
XMonad/Actions/ShowText.hs:91:44: warning: [GHC-63394] [-Wx-partial]
In the use of ‘head’
(imported from Prelude, but defined in GHC.List):
"This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
|
91 | (whenJust (lookup (fromIntegral $ head d) m) deleteWindow)
| ^^^^
Related: https://github.com/xmonad/xmonad-contrib/issues/830
I sort of ran out of steam at some point, but this is a good chunk of them. Most of these are relatively automatic replacements, only 5fc6777b could perhaps use a second pair of eyes, to see whether I've made any illegal transformations.
Commit summary
5fc6777b Reduce head usage
8f735acd Import X.Prelude unqualified if necessary
This gets rid of, for example,
-type warnings.
9399a1e8 X.{U,H}.Debug{Window,Events}: Replace tail with non-empty listsec3a9eea X.L.Groups: Rewrite gen using infinite streams
3a3544b5 X.Prelude: Add infinite stream type
Stolen from X.A.MostRecentlyUsed. This can be used in favour of lists when we know the generated lists are definitely infinite.
fab8ad5b X.U.Stack: Add differentiateTwo
cbb85248 Replace tail with drop 1
Where appropriate.
c8c81474 X.A.CycleWindows: Move rot{Up,Down} to X.A.RotSlaves
Reexport them instead.
Checklist
[x] I've read CONTRIBUTING.md
[ ] I've considered how to best test these changes (property, unit, manually, ...) and concluded:
I haven't installed GHC 9.8 (yet), so this is mostly untested. Everything should work, though.
[x] I updated the
CHANGES.mdfileWhere appropriate.
Remaining nits
Remaining nits…
XMonad/Layout/OneBig.hs:68:22: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 68 | master = head ws | ^^^^ XMonad/Layout/MultiColumns.hs:100:47: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 100 | where newval = max 0 $ head r + x | ^^^^ XMonad/Util/Image.hs:45:26: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 45 | imageDims img = (length (head img), length img) | ^^^^ XMonad/Actions/Workscreen.hs:112:40: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 112 | let ws = head . workspaces $ a !! wscrId | ^^^^ XMonad/Actions/SwapPromote.hs:243:30: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 243 | mh = let w = head . W.integrate $ s3 | ^^^^ XMonad/Hooks/ServerMode.hs:95:35: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 95 | let atom = fromIntegral (head dt) | ^^^^ XMonad/Actions/WorkspaceCursors.hs:100:34: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 100 | where x = end $ map return $ head a | ^^^^ XMonad/Util/Timer.hs:56:43: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 56 | if mt == a && dt /= [] && fromIntegral (head dt) == ti | ^^^^ XMonad/Hooks/Place.hs:196:49: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 196 | let (workspace, screen) = head infos | ^^^^ XMonad/Prompt.hs:537:21: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 537 | let defaultMode = head modes | ^^^^ XMonad/Prompt.hs:647:26: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 647 | return $ head l | ^^^^ XMonad/Prompt.hs:779:76: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 779 | if command st == hlCompl then put st else replaceCompletion (head cs) | ^^^^ XMonad/Prompt.hs:1386:13: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 1386 | let c = head s | ^^^^ XMonad/Prompt.hs:1594:43: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 1594 | (asc, desc) <- io $ textExtentsXMF fs $ head compl | ^^^^ XMonad/Prompt.hs:1795:25: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 1795 | deleteConsecutive = map head . group | ^^^^ XMonad/Actions/WindowGo.hs:93:70: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 93 | ifWindow qry mh = ifWindows qry (windows . appEndo <=< runQuery mh . head) | ^^^^ XMonad/Actions/WindowGo.hs:168:30: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 168 | _ -> windows . focusFn . head $ ws | ^^^^ XMonad/Prompt/OrgMode.hs:528:26: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 528 | str <- munch (/= head ptn) | ^^^^ XMonad/Hooks/StatusBar/PP.hs:467:14: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 467 | in fst $ head $ dropWhile (uncurry (/=)) $ zip xs $ tail xs | ^^^^ XMonad/Hooks/Minimize.hs:47:36: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 47 | let message = fromIntegral . head $ dt | ^^^^ XMonad/Util/ExclusiveScratchpads.hs:177:11: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 177 | mh <- head . map hook <$> ys -- ys /= [], so `head` is fine | ^^^^ XMonad/Util/ExclusiveScratchpads.hs:178:11: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 178 | n <- head . map name <$> ys -- same | ^^^^ XMonad/Layout/Combo.hs:124:63: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 124 | (maybe super head msuper') | ^^^^ XMonad/Layout/Combo.hs:125:60: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 125 | (maybe l1 head ml1') | ^^^^ XMonad/Layout/Combo.hs:126:60: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 126 | (maybe l2 head ml2') | ^^^^ XMonad/Layout/TallMastersCombo.hs:247:61: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 247 | let subMaster = if null w2 then Nothing else Just $ head w2 | ^^^^ XMonad/Layout/TallMastersCombo.hs:254:61: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 254 | let subMaster = if null w2 then Nothing else Just $ head w2 | ^^^^ XMonad/Actions/GridSelect.hs:661:61: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 661 | s = TwoDState { td_curpos = head coords, | ^^^^ XMonad/Util/EZConfig.hs:441:23: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 441 | combine ks = (head . fst . head $ ks, | ^^^^ XMonad/Util/EZConfig.hs:441:36: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 441 | combine ks = (head . fst . head $ ks, | ^^^^ XMonad/Util/EZConfig.hs:443:29: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 443 | fstKey = (==) `on` (head . fst) | ^^^^ XMonad/Util/EZConfig.hs:547:27: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 547 | dups = map (snd . head) | ^^^^ XMonad/Actions/Navigation2D.hs:887:38: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 887 | newwinset = winset { W.current = head newscrs | ^^^^ XMonad/Actions/Prefix.hs:169:37: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from XMonad.Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 169 | Raw a -> replicate a (head events) ++ [key] | ^^^^ XMonad/Actions/ShowText.hs:91:44: warning: [GHC-63394] [-Wx-partial] In the use of ‘head’ (imported from Prelude, but defined in GHC.List): "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty." | 91 | (whenJust (lookup (fromIntegral $ head d) m) deleteWindow) | ^^^^